From patent CH 705 238, a clamped flyweight balance wheel which allows adjustment of the inertia and/or of the balance is known. The balance wheel has two arms, each comprising a housing for receiving and clamping in position a rod of a flyweight. As a function of the direction of assembly of the balance wheel in the movement, it is possible that access to the flyweights positioned on the countersunk side of the balance wheel is difficult, or even impossible, and therefore requires dismantling. Furthermore, in the case where the distance between the stud and the inner diameter of the rim is too small, the flyweights can strike the stud, therefore having a damaging effect on good operation of the balance wheel.